William e



(No Model.)

W. E. GIBBS.

ELECTRIC DENTAL PLUGGER.

No. 427,070. Patented Mey 6, 1890.

me noms paens co., pHoro-umm, wAsHmcruN, o. c.

UNITED STATES lVlliLlAM E. GIBBS,

OF NElV YORK, N. Y.

ELECTRIC DENTAL PLUGGER.

SPECIFICATION for g part of Letters Patent No. 427,070, dated May 6, 1890.

Application filed January 14, 1889. Serial No. 296,363. (No model.)

T0 @ZZ whom t may concern:

3e it known that I, WILLIAM E. GIEBs, a citizen of the United States, residing in the city, county, and State ot New York, have invented certain new and useful Improvements in Electric Dental Pluggers, of which the following is a description.

In the accompanying drawings my improvements are shown as embodiedina single instrument having a number of distinctive parts.

Referring` to the drawings, Figure l is a view ot the plugger complete with the dental plugging-point attached. Fig. 2 is a longitudinal sectional view ot the complete instrument. Fig.3 shows for the sake of clearness part of the plugger in section and part in elevation, and Fig. 4 is a detail view of the toollliolder. j

In each ligure like lett-en referto the same parts.

My electric dental plugger consists Otan outer case A, of met-al, within which at one end is a tubular piece of soft iron D, having screwed or otherwise attached to one end a hollow conical section C, also ot sott iron. The parts B and O when conjoined form a hollow cylinder of uniform interior diameter, except at D, where the diameter of the bore is enlarged, as shown.

Nithin the cylinder formedv by the parts l and O is a loosely-iitting bar of iron E, (shown separately in Fig. 4,) having near its center an enlarged ring F. One end of the bar E is adapted to hold the dental pluggingpoint by being bored out and threaded,`or in any convenient way, while in the other end is a hole extending downward to the ring F. This loosely-1itting bar, being placed within the section B C, is pressed upward or toward B by a spiral spring inserted in the enlarged portion D of the bore of B and bearing on the enlarged ring F of the bar E. XVhen in position, as described, the ends of the bar E project slightly beyond the terminal parts ot' B and C, as shown in Fig. 2.

Vithin the tube A and beyond the iron parts B, C, and E slides freely an electro magnet formed of a soft-iron core ll, surrounded by a coil of insulated wire and having at each end a non-conducting washer G. I. rlhese washers are surrounded by short tubes of brass L K, which form within the tube A smooth bearing-surfaees. The wire upon the core ll has one ot its ends in electrical connection with said core and the other end similarly connected with the brass tube l). A coiled spring M within the bar F presses upon a rod of hard rubber, which bears upon the downward end of the core ll.

The upper end of the case A is closed by a plug of insulating material N, through which passes the circuitbreaker, constructed as vfollows: A brass cylinder ot thei'orm shown at O has within it a loosely-fitting sliding` bar ot iron l), the outer end ot' which is enlarged by a flange. A coiled spring surrounds this rod F, as shown in Fig. 2, and lightly presses it against the adj ustmcnt-screw R. The inner end of the iron bar l) projects through the cylinder O and rests in contact with the iron core ll of the electro-magnet, which in turn is pressed against the rod P by the retractin gspring M bearing upon the hard-rubber rod.

The action of my plugger is as follows: The wires marked being connected with a source of electricity of sufiieient power, the electric current comes in through the wire marked lto the circuit-breaker at O, passes down the rod P to the core ll ot' the electromagnet, through the insulated wire coil, and thence to the brass tube l., thence to the cas ing A, and back to the source by the wire all these parts being in electrical contact. The moment the current passes, the core .ll becomes Inagnetized and is violently drawn toward the lower end et the instrument by the mutual attraction between the magnet ized core ll and the mass of iron t'orming the parts l, O, and E, the spring M yielding as the parts come together. The core ll, by virtue of its magnetic force, draws down the rod F of the circuit-breaker with it, the spring surrounding the rod yielding as the rod advances. ing coil of wire, reaches the end of its downward stroke, it comes in contact with the plugging-point-holding bar E, and the blow is by this bar transmitted to the plugger or point, and by it to the geld or other iilling impacted in the tooth; but when the core H comes in contact with the end of the barli. the electric current is no longer compelled to pass through the long coil of wire upon the core ll', but

lVhen the core ll, with its surround` ICO takes a more direct road from the core II through the parts B and E directly to the outer case A, thus cutting the coil ont of the circuit. As soon as this happens the core IVI becomes demagnetized and no longer draws upon the circuit-breaking rod P, which is thrown back into contact with the adjustment *screw R by the spring surrounding it. The retractingspring M immediately returns the electro-mag net to its original position and the operation is repeated so long as the current is applied. It is of the utmost importance that this opw eration should be effected without any adhesion or hesitation on the part of the different parts of the instrument brought into con j unction and released by the shifting of the current, as hereinbefore described. To obviate a defect in this particular which was found to eXist to the impairment of the utility of my invention, I face the upper end of the core II with a thin plate or washer of platinum and screw or otherwise fasten into the lower end of the sliding rod P a button or point of platinum, so that the contact of the core I'I and sliding bar P is made upon this metal and instantaneously severed upon the shifting of the current after the blow is delivered upon the rod E. By means of these points or washers of platinum the burning of the ends of the soft-iron core I-I and rod P by the passing` current, and also any tendency to the adhesion of those parts because of the residual magnetism remaining' after the shift-ing of the current, are avoided.

In all vibrating electrical instrumen ts hit-herto invented the circuit is broken just before the blow is given, thereby losing the .force of the magnetic attraction, which is strongest at the moment of contact of the armature and the magnet.

I am aware that electro-magnetic dental pluggers have been invented havingl many of the features embraced in my invention; but4 nearly all of those features were common to the arts and nnpatentable as separate inventions; but none of these prior instruments have been found of sufficient practical use by dentists to warrant their application to the purposes for which they were intended to be applied and have been for the most part dispensed with. One of the defects of such instruments which rendered them comparatively useless was the breaking of the electric current, as hereinbefore explained, before contact between the armature and the magnet, and consequently before the delivery of the blow, which my invention overcomes.

I make no claim upon any portion of the instrument embraced in this specification con tained in thelower section thereof, or so much as is shown beyond the lower termination of the core II downward, as such parts consist either singly or in combination of hitherto well-known devices; but

lVhat I claim as myinvention, and desire to secure by Letters Patent, is-

l. The combination of the sliding bar P, maintained in electrical connection with the core II by the retracting-spring M, the core H, the non-conducting washers G I at either end of the core II, surrounded by the brass tubes L K, and the wire upon the core II in electrical connection with the core II and the brass tube L, for the purpose and substantially in the manner herein described.

2. The combination of the circuit-wires -land with the circuit-breaker O, the circuite breaking rod P, the sliding electro-magnet core II and its surrounding coil, the outer casing A, and the armature Il, for the purpose and substantially in the manner herein described.

, IVILLIAM E. GIISBS.

lVitnesses:

NELsoN Cnoss, LEONARD S. WHEELER. 

